Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With annotations present, the description still adds real value: it says the change applies from the next check onward, that past answers are not re-read, that duplicates by name/site are rejected, and that the call runs immediately as the acting person. That's substantive side-effect and authorization context beyond readOnly/destructive hints; only the return/error shape is left implicit (though an output schema exists).

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with the action and the fields it affects, then the timing and dedupe rules. It runs a little long with the closing 'A change inside Kooga' line, but every sentence carries behavioral information rather than restating the schema.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a mutating tool with four parameters, a dedupe rule, and a self-exclusion rule, the description covers timing of effect, uniqueness constraints, and where to read the result. An output schema exists, so return values need not be explained; only workspace scoping is left to the schema alone.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already defines all four parameters, and the description adds only conceptual framing (site, alternate engine names, self-exclusion). The workspaceId parameter is not mentioned at all, so the description does not fully relieve the agent of reading the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource (add a competitor) and names the concrete fields it captures — name, site, aliases. It also distinguishes the tool from readCompetitors by stating that listing is done via readOptions with kind competitors, so an agent can tell which one to call.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description makes the use case and constraints explicit: dedupe by name or site, the brand cannot be its own competitor, and the resulting list is read via readOptions. It doesn't spell out explicit when-not-to-use or contrast against any other sibling beyond that, so it stops short of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.